Centrifugal apparatus

ABSTRACT

A CENTRIFUGAL APPARATUS INCLUDING A ROTATING SUPPORT MEMBER FOR SUPPORTING SAMPLE CONTAINING VESSELS AND A DISTRIBUTING CHAMBER ROTATABLE WITH THE SUPPORT MEMBER AND ADAPTED TO RECEIVE LIQUID FROM DISTRIBUTING THE SAME THROUGH CANNULAS TO THE VESSELS. THE PRESSURE IN THE DISTRIBUTING CHAMBER IS VARIED PERIODICALLY TO VARY THE LEVEL   OF THE LIQUID IN THE VESSELS, AND HENCE TO AGITATE THE SAID LIQUID IN THE VESSELS.

p 20, 1971 J. E. H. WESTBERG 3,606,142

CENTRIFUGAL APPARATUS Filed July 9, 1969 2| l5 l0 I United States Patent3,606,142 CENTRIFU GAL APPARATUS Johan Eric Hayden Westberg, Lidingo,Sweden, assignor to AGA Aktiebolag, Lidingo, Sweden Filed July 9, 1969,Ser. N 0. 840,220 Claims priority, application Sweden, July 10, 1968,9,47 4/ 68 Int. Cl. B0111 21/26; B04b 1/20, /02 US. Cl. 233-1A 10 ClaimsABSTRACT OF THE DISCLOSURE A centrifugal apparatus including a rotatingsupport member for supporting sample containing vessels and adistributing chamber rotatable with the support member and adapted toreceive liquid for distributing the same through cannulas to thevessels. The pressure in the dis tributing chamber is variedperiodically to vary the level of the liquid in the vessels, and henceto agitate the said liquid in the vessels.

BACKGROUND OF THE INVENTION This invention related to centrifugalapparatus; and in particular, it relates to a means for agitatingmaterials being treated in a centrifugal apparatus.

In the operation of a centrifugal apparatus it is necessary to keep theparticles in the liquid in suspension so that they will be accessible towashing or other treatment with the liquid. This has been accomplishedheretofore by mechanical stirring processes. For example, the cannulascarrying liquid from a central location into the vessels have beenimmersed periodically thereby causing stirring of the liquid therein.However, this process has several disadvantages. On the one hand, arather complicated apparatus is necessary in order to carry out theperiodic insertions and removal of the cannulas. Further, the mechanicalaction can have an undesirable effect on the particles suspended in theliquid. This is particularly true if the sample material is blood andthe suspended particles are blood corpuscles.

Thus, there exists a need for a new and improved means for effectingagitation of the liquid in the vessels of a centrifugal apparatus, whichmeans is more simplified than means known heretofore, and which meansWill not have an adverse effect on the particles suspended in theliquid.

SUMMARY OF THE INVENTION A purpose of the present invention is toprovide a new and improved arrangement for agitating the liquid in acentrifugal apparatus, which arrangement overcomes disadvantages in thedevices known heretofore.

This purpose of the present invention is carried out by providing anarrangement wherein a gentle but nevertheless eflicient agitation isobtained by varying the pressure, and hence also varying the level ofthe liquid in the sample containing vessels. More specifically, a meansis provided for pulsating the pressure in the vessels thereby causingthe liquid therein to oscillate, whereby agitation of the liquid in thevessels is obtained.

According to a preferred arrangement of the present invention, there isprovided a support member mounted on a frame for rotation about an axisand including means for supporting one or more sample containingvessels. A distribution chamber is located on or about the axis ofrotation and is also rotatable about the said axis. This chamberincludes means for receiving a liquid to be subsequently delivered tothe individual sample vessels, and also a separate aperture for each ofthe said vessels. A suitable conduit means extends from each of the saidapertures into its respective sample vessel and to a point PatentedSept. 20, 1971 ice therein below the normal level of the liquidcontained therein. Thus, in operation as a centrifugal apparatus, thesupport member, the sample vessels and the distributing chamber are allrotated, in unison, as a result of which liquid flows from thedistributing chamber through the conduit means to the respective samplevessels, and of course the centrifugal force is applied to the liquid inthe vessels as the said members rotate about said axis.

In accordance with a main feature of the present invention, a means isprovided for pulsating the pressure in the distributing chamber.Consequently, the pulsating pressure is felt by the liquid in the saidvessels at the outer end of the conduit means. The vessels themselvesare exposed at their upper ends to atmosphere so that the pres surevariation in the conduit means causes the level of the liquid in thevessels and in the conduit means to oscillate, thereby agitaing the saidliquid.

In accordance with the present invention various means may be providedfor causing the said pulsating pressure in the distributing chamber. Forexample, in one embodiment of the invention a pulsating device such as avibrating diaphragm can be connected directly through a conduit, whichwould be concentric with the axis of rotation, into the distributingchamber. In another embodiment a continuous pressurized fluid pipe and avent opening can be placed into fluid communication with thedistributing chamber and in combination therewith an element rotatableWith the distributing chamber to alternately obstruct first the pressurepassage and then the vent passage to cause the said pulsating pressurein the distributing chamber.

Thus, it is an object of this invention to provide a new and improvedarrangement for agitating the liquid in a centrifugal device.

It is another object of this invention to provide a new and improvedcentrifugal device including a means for agitating the liquid thereinwithout mechanically contacting the liquid.

It is another object of this invention to provide an arrangement foragitating the liquid in a centrifugal apparatus by applying a pulsatingpressure to the liquid in the vessels thereby causing the said liquid tooscillate.

It is still another object of this invention to provide a new andimproved centrifugal apparatus having a support member for supportingand rotating sample vessels and including a rotating centrally mounteddistributing chamber, and including means for pulsating the pressurewithin the distributing chamber and consequently pulsating the pressureof the liquid in the vessels to agitate the said liquid.

Other objects and the attendant advantages of the present invention willbecome apparent from the detailed description to follow together withthe accompanying drawmgs.

BRIEF SUMMARY OF THE DRAWINGS There follows a detailed description ofpreferred embodiments of the present invention, to be read together withthe accompanying drawings. However, it is to be understood that thedetailed description and accompanying drawings are provided only forpurposes of illustration and that the invention is capable of numerousmodifications and variations apparent to those skilled in the art.

FIG. 1 is a vertical cross-sectional view through the center of theapparatus and showing the center part and the elements on one sidethereof, and omititng, for purposes of clarity, the identical part onthe other side of the center part.

FIG. 2 is a vertical cross-sectional View taken through the center of afurther embodiment of the invention and also showing, in addition to thecentral parts, certain 3 portions only on one side of the center line,omitting the corresponding parts on the opposite side for purposes ofclarity.

FIG. 3 is a partial sectional view taken along a plane passing throughline 33 of FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to thedrawings, FIG. 1 illustrates a first embodiment of the invention andFIGS. 2 and 3 illustrate a second embodiment of the invention. Ele mentsin the second embodiment which correspond to elements in the firstembodiment are indicated by the same numeral with a prime Further, forpurposes of clarity, the drawings show only those parts of theembodiments located on one side of the central axis of the centrifugalapparatus. It is to be understood, however, that both embodiments haverotational symmetry about this axis. Further, while only a single vesselis illustrated in FIG. 1, it is to be understood that any number ofelements may be provided about the said central axis.

Referring now to FIG. 1, the apparatus includes a fixed housing part 1having rotatably mounted therein a ro tating support member 2 which isconnected to the housing 1 through roller bearings 3. Rotationalmovement of the support member 2 is provided by a motor 6 which actsthrough a belt to drive a belt pulley 4 which is fixed to the supportmember 2 for rotation therewith.

The support member 2 includes a plurality of recesses, only one of whichis shown in the drawings, for receiving and supporting a sample vessel7. This vessel includes an end opening 8 facing upwardly and radiallyinwardly.

A distributing chamber 10 and a central tubular member 12 areoperatively connected to the support member 2 for rotation therewith.This connection is shown diagrammatically at 40 in FIG. 1. Thedistributing chamber 10 includes a plurality of apertures 11 spacedabout the outer periphery thereof. Connected to each aperture 11 is aconduit means in the form of cannula 9 which places the interior of thedistributing chamber 10 into fluid communication with the bottom of asample vessel 7.

Liquid is supplied to the distributing chamber 10 by means of a pipe 13which is non-rotatably fixed with respect to the fixed housing 1 andwhich extends through the central tubular member 12, and through a fluidseal 24, and through the upper opening 14 of the central tubular member12 and into the distributing chamber 10. Upon rotation of the apparatusand owing to the centrifugal force, the liquid in the chamber 10 willthen be urged against the outer annular surface 15 of the chamber 10from which it will pass through the outlets 11 and the cannulas 9 intothe sample vessels 7.

When centrifuging is performed and the liquid is supplied in this mannerto the sample vessels, a surplus of liquid can drain otf either throughthe opening 8 or, as indicated in the drawings, through an outlet 16which is provided at a greater distance from the axis of rotation thanthe end opening 8. In this case, the liquid will collect in an annularspace 17 formed in the supporting member 2; and to insure that theliquid passing through opening 16 is in fact directed to this space 17,the opening 16 is provided with a tubular section 18. The liquidcollected in this manner in the space 17 can then flow ofi after thecentrifuging has been completed through the aperture 19 formed in thesupporting member 2 and subsequently through a drain tube 20 leadingfrom the illustrated portion of the fixed housing 1.

To provide agitation of the liquid in the vessels at the desired times,so as to cause the particles in the vessels to rise from the bottomsthereof and be suspended, the chamber 10 is connected through a fluidseal O-ring 23, by means of a pipe 21 to a suitable pulsating device 22.By way of example, this device may comprise a motor operated vibratingdiaphragm, one side of the diaphragm enclosing a chamber in fluidcommunication with the pipe 21.

The apparatus of FIG. 1 would operate as follows. With support member 2at rest, a number of sample vessels 7 are inserted onto the apparatus.Each of these vessels can be assumed to contain a small amount of liquidhaving solid particles therein. Such a liquid with solid particles canbe blood, and the solid particles are then blood corpuscles to bewashed, for example. The support member 2 is then rotated and liquid issupplied through the tube 13. The primary purpose of this liquid wouldbe to dilute the liquid in the sample vessels 7. After a certain amountof cleaning liquid has been supplied, the pulsating device 22 can beoperated for creating a pulsating pressure in the chamber 10. As aresult of this, the liquid in the cannula 9 will oscillate about amedian position which can be assumed to be represented by the dash line25 in FIG. 1. The liquid in the cannula 9 will therefore be periodicallybe ejected from and withdrawn into the cannulas 9, thereby agitating theliquid in the cannulas 9 and of course also in the sample vessels 7.

The pulsating device 22 for creating the pulsating pressure in thecontainer 10 might then be stopped, after which the particles suspendedin the liquid would be centrifuged down towards the bottom or the radialoutward end of the vessels 7. At this time additional liquid could besupplied through the tube 13 until liquid flows out of the openings 16and 8. When the cleaning liquid has been exchanged in the sample vessels7 in this manner, the pulsating device 22 may once again be started,after which the above described process is repeated any number of times.After the required washing has been completed, the supporting member 2is stopped and the vessels 7 can be removed.

FIG. 2 illustrates another embodiment of the invention. This embodimentis similar to FIG. 1 in most respects, and hence many of the elementsshown in FIG. 1 are omitted from FIG. 2. The main difference is that theembodiment of FIG. 2 illustrates another arrangement for causing thepulsating pressure in the distributing chamber.

In FIGS. 2 and 3 the central tubular member 12' is fixed with respect tothe frame 1' and it is provided with a cover member 27, preventingliquid from flowing from the distributing chamber 10 down into thetubular member 12. The upper portion of chamber 10 is closed by asealing lid 26. A fluid inlet tube 13 passes through the tubular member12' and the cover 27 for introducing liquid into the distributingchamber 10'. However, in this case, since the tubular member 12' doesnot rotate, it is not necessary that the pipe 13' be located on the axisof rotation of the distributor chamber 10'. A bearing surface 28 isprovided between the engaging portions of the chamber 10' and thecentral tubular member 12'. A means for operatively connecting thechamber 10' with the member 2' for rotation therewith is showndiagrammatically at 41 in FIG. 2.

It will be noted that the upper portion of the tubular member 12'extends well into the distributor chamber 10. On one side, this upwardlyextending portion has an opening 30 in constant fluid communication witha conduit 29 through which compressed air would be continuouslysupplied. On the opposite side of the tubular member 12 there isprovided an opening 31 for venting the distributing chamber 10. Thedistributing chamber 10' includes an upwardly extending semicircularflange 32 which rotates therewith, continuously encircling the saidupstanding portion of the tubular member 12'.

Thus, it can be seen that in operation, during one half-turn of thedistributing chamber 10 (the half-turn illustrated in FIGS. 2 and 3) thechamber 10' is pressurized by means of its communication with conduit29. After the chamber 10 has rotated one half-turn, the aperture 30 isclosed by the flange 32, thereby breaking the connection to pressurefluid pipe 29, and the aperture 31 is then opened to vent the chamberthereby permitting a reduction in the pressure therein. This process isrepeated periodically upon rotation of the chamber 10'.

Although the invention has been described in considerable detail withrespect to preferred embodiments thereof, it will be apparent that theinvention is capable of numerous modifications and variations apparentto those skilled in the art without departing from the spirit and scopeof the invention. For example, in either embodiment the pulsatingprocedure need not take place continuously but can be set to take placeonly at specified times during the centrifuging process. Othermodifications and variations are also apparent.

I claim:

1. A centrifugal apparatus comprising a frame, a support member mountedon the frame and rotatable about an axis, said support member includingmeans for mounting at least one vessel thereon for rotation therewithabout said axis, a distribution chamber also rotatable about said axis,conduit means normally placing said chamber in fluid communication withsaid vessel, and means for periodically varying the pressure in saidchamber, thereby also varying the pressure in said vessel, whereby thelevel of any liquid present in the vessel is caused to vary, therebycausing agitation of such liquid.

2. The apparatus of claim 1 wherein said vessel includes a vent openingfacing toward said axis, and said conduit means comprises a passageextending from said distribution chamber to a point in said vessel belowa normal liquid level thereof, such that when liquid is present in thevessel to' 'a level above said point and the pressure in thedistribution chamber varies, the liquid level varies in the passage andhence also in the vessel, thereby agitating the said liquid.

3. The apparatus of claim 2 including a plurality of said vessels onsaid support member and spaced about said axis radially outwardly fromsaid distribution chamber, said conduit means comprising a separatepassage leading from said distribution chamber to each vessel.

4. The apparatus of claim 2 wherin said axis is substantially verticaland said support member rotates thereabout in a substantially horizontalplane, and wherein said passage is a cannula extending radiallyoutwardly from said distribution chamber and passing downwardly throughsaid vent opening to the lower part of said vessel.

5. The apparatus of claim 2 wherein the means for periodically varyingthe pressure in the distribution chamber varies the pressure in aregular cyclical manner.

6. The apparatus of claim 5 wherein the means for varying the pressurecomprises a fluid pulsating device, and a pipe leading from said deviceinto said distribution chamber.

7. The apparatus of claim 6 wherein said pipe is nonrotatably mounted onsaid frame, a fluid type seal, and wherein said pipe extends along saidaxis and through said seal into the chamber, whereby the chamber isrotatable relative to the pipe.

8. The apparatus of claim 7 including a central tubular member attachedto and rotatable with said chamber about said axis, and a fluid inlettube non-rotatably mounted on the frame and passing through said sealand through said tubular member along the said axis and entering thechamber across from the said pipe, said inlet tube being adapted todeliver liquid to the interior of said chamber, whereby the chamber isrotatable relative to the inlet tube.

9. The apparatus of claim 5 including a first passage and a secondpassage leading to said chamber wherein said means for varying thepressure in the distribution chamber comprises a means for continuouslysupplying pressurized fluid to said first passage leading to saidchamber, and wherein said second chamber leads from said chamber tovent, and means for alternately obstructing each of said first andsecond passages while leaving the other passage open to the chamber.

10. The apparatus of claim 9 including a tubular member non-rotatablymounted on said frame along the said axis, the said distribution chambermounted on said tubular member for rotation thereabout, the said firstand second passages leading from said tubular member to said chamber,and wherein said means for alternatively obstructing said passagescomprises a flange rotatable with the chamber and operable toalternatively cover said first and second passages.

References Cited UNITED STATES PATENTS 2/1966 Unger 23326X 4/1969 Unger233-3 US. Cl. X.R.

